Half Dome

Half Dome is Yosemite’s best-known granite landmark, rising nearly 5,000 feet above Yosemite Valley. Its rounded crown and sheer northwest wall make it look as though a giant piece broke away, but more than half the dome remains. You can see it from the Valley without hiking to the summit; standing on top is a very different undertaking.

The summit hike is a full-day effort: 14 to 16 miles round trip, about 4,800 feet of climbing, and usually 10 to 12 hours. The route is a sustained uphill walk before you reach the steepest ground. If the distance, height or exposure sounds like more than you want, enjoy Half Dome from a Valley viewpoint instead.

Most hikers start at Happy Isles, shuttle stop 16, and climb past Vernal Fall and Nevada Fall, then Liberty Cap and Little Yosemite Valley, before reaching Subdome and the final granite slope. Add the walk to Happy Isles: about half a mile from the trailhead parking lot or three-quarters of a mile from Curry Village parking. Set a firm turnaround time; the park recommends leaving around sunrise or earlier and carrying a headlamp with spare batteries for the descent.

Carry food and enough water for the whole day. The only treated water point on the route is a summer drinking fountain at Vernal Fall Footbridge; river water farther along needs treatment. The park lists flush toilets at the footbridge and composting toilets near Emerald Pool, near the top of Nevada Fall and in Little Yosemite Valley, all before the summit.

From the top, the view opens across Yosemite Valley and the High Sierra. For a close look without the summit hike, Mirror Lake is reached by a paved two-mile round trip and gives a nearer view of the face. You can also see Half Dome from roads in eastern Yosemite Valley, including between Yosemite Village and Yosemite Valley Lodge and near Curry Village. Those are useful places to frame the dome against the Valley; the summit pin itself is not a drive-to stop.

Half Dome is granodiorite that crystallized deep underground and became exposed as the landscape rose and eroded. Pressure release let curved sheets of rock peel away and round the crown, while vertical joints helped define the sheer face. Glaciers undercut and plucked at the rock, and rockfalls continue to alter it. The familiar “half” profile formed gradually rather than when a whole side split off.

A report in 1865 called the high point inaccessible. George Anderson reached the summit in 1875 and laid the predecessor of the cable route hikers use today. The cables made the final slope reachable without turning it into a technical rock climb, though the full outing remains long, strenuous and exposed.